As temperatures begin to rise, it’s time to begin thinking about one of the great pleasures of springtime: an afternoon sitting under the shade of a blossoming tree, stationed at a long table, hoisting a liter mug of beer. Maybe even playing a game of dominoes.

Yes, beer garden season has arrived. So let’s take the time to thank two groups of people — the Germans who invented lager, and the Germans who immigrated to the U.S. in the second half of the 19th century. If it weren’t for them, baseball would likely be our only excuse to sip suds in the sun.

Unlike the ales that constituted all the world’s beer before the middle of the 19th century, the lager yeasts discovered in Bavaria at that time required a different type of fermentation. Ales — produced through the addition of top-fermenting yeast — ferment rapidly, at warm temperatures. Lagers, contrarily, depend on a slow, cool fermentation, ideally at temperatures between 45 and 56 degrees Fahrenheit. And after fermentation is complete, they need to be stored and aged for several months, at even cooler temperatures.

This was an era before refrigeration, however, so Bavarian brewers dug out large underground cellars for stashing the barrels while the beer "lagered." To ensure fuller protection from the sun, they then scattered gravel over the ground and planted leafy chestnut and linden trees, which, as they grew, would provide ample shade from the sun.